Estimation and analysis of catamaran resistance by XFlow CFD software

Abstract

Ships operating in rivers because they have a small L/B ratio, so they are easy to maneuver in rivers and small d draft suitable for shallow water. Along with that development, bringing in bifurcation resistance is topical because accurate estimation of the ship resistance will help to choose the correct propulsion capacity that leads to significant cost savings. Popularly today, methods of calculating fluid dynamics (CFD) are used to estimate resistance. The CFD methods are usually based on the Navier - Stokes equations and the accuracy of the solution depends on the computational domain, the physical conditions at the boundary also depend on the mesh structure (number of grid levels, a boundary position of the grid level, grid size, etc.). Therefore, if the meshing work is not reasonable, it will lead to inaccurate calculation results, worse, the solution may not converge. Recently, the CFD method based on liquid particles system, Lattice Boltzmann Methods (LBM), has been recognized as an alternative to overcome the disadvantages of the meshing process. In this study, we use the XFlow program built based on the theory of liquid particle interaction according to LBM to simulate the motion of the river bus catamaran moving in static water with two degrees of freedom (2DOF) and from that which estimates the resistance of the vessel.